Spring coiling machine



Nov. 24, 1970 T. D. HANSEN SPRING COILING MACHINE Filed April 1 1968 4 Sheets-Sheet 2 If 1 24 Fig 3 42 III T "riT fi' ififi Tiinmnmi- 64 46 /4 Fly I0 52.

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Nov. 24, 1970 1'. D. HANSEN 3,541,827

SPRING COILING MACHINE Filed April 16, 1968 4 Sheets-Sheet 5 Fig. 7

Thelma 0. Hansen INVENTOR.

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Thelma D. Hansen IN VIZNTOR. 4052'. Wave M United States Patent 3,541,827 SPRING COILING MACHINE Thelma D. Hansen, Rte. 2, Box 1A, Vale, Oreg. 97918 Filed Apr. 16, 1968, Ser. No. 721,699 Int. Cl. B21f 3/10, 11/00 US. Cl. 72132 12 Claims ABSTRACT OF THE DISCLOSURE A power operated wire coiling machine for forming coil springs by feeding stock wire between guides closely spaced from an externally groved forming element which is rotated in synchronized relation to the feeding movement of the wire. The coils being formed to one side of the rotational axis of the forming element are engaged by a plunger axially displaced by a cam device. The cam device is operated by the drive shaft for the forming element to effect severing of the coils from the wire by a cutter blade mounted on the forming element.

This invention relates to a machine for making coil springs of the type in which wire is continuously fed against a forming surface bending it into a coil.

The present invention is concerned with the precision manufacture of special coil springs from stock wire by wire coiling machines. Such machines are relatively small and find particular use in tool rooms, repair, design and model shops as distinguished from high speed production installations. Thus, the wire coiling machine must be capable of producing coil springs of different pitch and diameter as well as coil springs having different diameter portions.

In accordance with the present invention, the formation of special coil springs from stock wire is effected in a novel manner which permits the user to readily change or adjust the coiling machine in order to meet different requirements such as wire diameter, coil pitch and coil diameter. Further, a coil spring having different diameter sections may be formed in one operation or coil pitch automatically varied without requiring any change in the machine setup. Also, after a predetermined number of coils are formed, the spring is automatically severed from the wire.

Despite the versatility of the spring coiling machine of the present invention, it is capable of precision operation because the wire is pushed into shape against a forming surface rather than being wound on an arbor. The forming surface is constituted by an annular groove in the outer periphery of a cylindrical forming element which is rotated at a speed synchronized to the feeding movement of the wire. The wire is guided along a path slightly offset from the rotational axis of the forming element so that when the wire enters the external groove in the forming element, it will coil to one side of the rotational axis. The spacing of the bottom of the groove in the forming element from the wire guide determines the coil diameter. By utilizing a forming element having a groove of different depths, coils of different diameter may be formed. Also projecting radially from the forming element, is a cutter blade adapted to sever the coils from the wire being fed from the guide into the forming groove of the forming element. Cut-0E of the coils is effected by axial displacement of the last coil formed, into the path of the cutter blade so that it may be properly sheared. A coil displacing plunger accordingly engages the coils and its axial movement is controlled by a cam device driven by the shaft through which rotation is imparted to the forming element from the same motor which operates the wire feeding rolls to automatically vary coil pitch.

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These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a front elevational view of a wire coiling machine constructed in accordance with the present invention.

FIG. 2 is a side elevational view of the machine shown in FIG. 1.

FIG. 3 is a top plan view of the machine shown in FIGS. 1 and 2 with a portion broken away.

FIG. 4 is an enlarged partial sectional view taken substantially through a plane indicated by section line 4-4 in FIG. 1.

FIG. 5 is an enlarged partial top sectional view taken substantially through a plane indicated by section line 5-5 in FIG. 1.

FIG. 6 is an enlarged partial sectional view taken substantially through a plane indicated by section line 66 in FIG. 1.

FIG. 7 is an enlarged front elevational view of a portion of the machine with parts broken away and shown in section.

FIG. 8 is a partial sectional view taken substantially through a plane indicated by section line 8-8 in FIG. 7.

FIG. 9 is a partial sectional view taken substantially through a plane indicated by section line 99 in FIG. 8.

FIG. 10 is a partial sectional view taken substantially through a plane indicated by section line 10-10 in FIG. 7.

FIG. 11 is a partial sectional view showing formation of a special coil spring in a phase following that of FIG. 8.

FIG. 12 is a side elevational view of a completed coil slpring made on the machine illustrated in FIGS. 1 through FIG. 13 is a partial front elevational view of the machine conditioned for variable pitch control of coil springs.

FIG. 14 is an enlarged partial sectional view taken substantially through a plane indicated by section line 14 14 in FIG. 13.

Referring now to the drawings in detail, FIGS. 1, 2 and 3 illustrate the wire coiling machine in its entirety which is generally denoted by reference numeral 10. The machine is supported on a suitable surface by means of its base plate 12 to which a front mounting frame structure 14 is secured extending vertically upwardly in spaced relation to a rearwardly mounted housing 16 for an electric motor operated reduction gear assembly from which a pair of output shafts 18 and 20 extend driven at a fixed drive ratio to each other. The motor gear assembly enclosed within the housing 16 is accordingly operative to control the coil diameter and cut-off of the coil spring formed by the machine in synchronized relation to the feeding of stock wire 22 being unwound from a suitable source (not shown) such as a Wire spool.

The output shaft 18 of the motor gear assembly mounts a drive pulley 24 about which a crossed drive belt 26 is entrained for transmitting rotation to a driven pulley 28 connected to one end of a feed control shaft 30 journaled by the journal blocks 32 and 34 extending rearwardly from the front mounting structure 14 as more clearly seen in FIG. 3. The feed shaft 30 operates the wire feeding mechanism associated with the machine which is generally referred to by reference numeral 36. The wire feeding mechanism includes a worm gear 38 mounted on the end of the feed shaft 30 in mesh with a Worm wheel 40 enclosed within the hood 42. The Worm wheel is connected to the end of shaft 44 which is journaled by the front mounting structure 14. Connected to the end of the shaft 44 opposite the worm wheel 40, is a feed wheel 46 adapted to engage the wire 22 being fed downwardly through an aperture in a guide element 48 secured by fastener 50 to the top of the front structure 14. The wire is also engaged by a second feed wheel 52 connected to one end of a shaft 54 rotatably mounted by the upper journal portion 56 of a mounting arm 58 as more clearly seen in FIGS. 1, 2, 3 and 5. Th mounting arm is pivotally secured to the mounting structure 14 by a pivot pin 60 located adjacent the mounting base 12 as shown in FIG. 1. A lock shaft 62 is provided in order to lock the mounting arm 58 in an adjusted position in order to hold the feed wheel 52 closely spaced from the feed wheel 46 for engaging the wires 22 as both feed wheels are rotated in opposite directions. The feed wheel shafts 54 and 46 are accordingly provided with externally toothed spur gears 64 and 66 in mesh with each other.

The Wire 22 being fed downwardly by the feed wheels 46 and 52, passes between a pair of guide plates 68 and 70 adjustably mounted on the front mounting structure 14 below the feed wheels by means of the mounting elements 72 as more clearly seen in FIG. 6. The guide plates are adjusted relative to each other by means of a pair of adjustment brackets 74 and 75 secured by fasteners 76 to the mounting structure 14, each adjustment bracket having a pair of adjustment screws 78 projecting into engagement with the guide plate supported on the front mounting structure 14. As more clearly shown in FIGS. 4 and 7, a wire guiding groove 84 is formed in plate 70 to establish a precision feed path for downward feeding of the wire 22 into engagement with a cylindrical forming element disposed in close spaced relation below the guide plates. The guide plates 68 and 70 are adjustable as aforementioned in order to accommodate wire of dilferent thicknesses and to establish a guide path which intersects the forming element 80 in close offset relationship to the rotational axis of the drive shaft 88 to which the forming element 80 is connected. As more clearly seen in FIGS. 7 and 8, the forming element 80 is cylindrical in shape and is externally grooved so as to present a forming surface 90 against which the wire 22 is pushed by the feeding mechanism causing it to coil to one side of the rotational axis of the forming element. In the illustrated embodiment, the forming surface 90 is formed at the bottom of groove portions 92 and 94 of different depths so that the diameter of the coil into which the wire is bent will change as a function of the forming elements angular movement.

Mounted within the forming element 80 and projecting radially therefrom between the groove portions 92 and 94, is a cutter blade 96 presenting a shearing edge which extends laterally across the grooves at an appropriate cutting angle to the rotational axis of the forming element. The cutter blade is adjusted to a radially projecting position by the adjustment screw as shown in FIG. 10 and is locked in its adjusted position by the overlapping washer 97 secured to the forming element by fastener 99. The cutter blade 96 in cooperation with a fixed cut-off blade 82 is effective to sever a coil spring from the wire after a predetermined number of coils are formed as will be explained hereafter in detail. As shown in FIGS. 8 and 9, the blade 82 is exposed through a recess formed at the lower corner of the guide plate 68 confronting guide plate 70. The blade 82 is adjustably positioned by its mounting portions 83 pivotally received in support disc 85 rotatably mounted in the frame structure 14 behind the Wire coiling point. Elongated locking screws 77 and 79 etxend from the bracket 75 through the guide plate 68 to engage, adjust and hold the blade 82 in its adjusted position for cutoff of the wire 22 as shown in FIG. 9. Although square cut blades 82 and 96 are shown, it will be appreciated that angle cut blades could also be used.

The drive shaft 88 for the forming element is rotatably mounted between the front mounting structure 14 and the housing 16 of the motor gear assembly. A pulley wheel 98 is connected to the drive shaft 88 adjacent the housing 16. An endless drive belt 100 is entrained about the pulley wheel 98 and a drive pulley 102 secured to the output shaft 20 projecting from the housing 16 so as to impart drive to the forming element 80 through the drive shaft 88 in synchronized relation to the continuous feed of the wire 22.

An axial cam member 104 is secured by a setscrew 106 to the drive shaft 88 between the front mounting structure 14 and the pulley wheel 98 for rotation with the drive shaft. The cam member 104 engages a cam follower member 108 slidably mounted on the drive shaft 88 for axial displacement in response to rotation of the cam member 104 by the drive shaft. The cam follower memebr 108 is connected to an upwardly extending follower arm 110 as shown in FIG. 2. The follower arm is connected to a plunger rod 112 which mounts a spring 114. The spring 114 reacts between the front mounting structure 14 and the follower arm 110 in order to continuously bias the cam follower member 108 into engagement with the cam member 104. The plunger rod 112 is slidably mounted by the front mounting structure 14 and extends therethrough. A coil engaging formation 116 is connected to the plunger rod on the front side of the mounting structure 14 and is adapted to project into a coil receiving recess 118 formed in one of the guide plates 68 on one side of the rotational axis of the forming element. The coils into which the wire 22 is bent by engagement with the forming surface 90 on the forming element, will be formed in concentric relation to the coil engaging portion 116 of the plunger rod as the rod is axially displaced by the cam member 104 to automatically vary coil pitch in accordance with the setting of the cam member 104.

FIG. 8 illustrates the beginning of a coiling operation in which the wire is received within the deeper groove portion 92 of the forming element 80 so as to form a smaller diameter coil 120 about the coil engaging plunger portion 116. Accordingly, as the wire continues to coil additional coils 120 are formed as the coil engaging plunger 116 moves outwardly under control of the cam member 104. At the same time, the forming element 80 is rotated so that when a predetermined number of small diameter coils 120 are formed, the wire engages the forming surface in the shallower groove portion 94 of the forming element as shown in FIG. 11. Larger diameter coils 122 are then formed as the coil engaging portion of the plunger begins to move axially inwardly. It will be noted, that the smaller diameter coil 120 is of a diameter sufficient to be received within the recess 118 formed in the guide plate 68. Thus, a predetermined number of larger diameter coils 122 are formed and the smaller diameter coils 120 displaced into the recess 118 just before the rotating forming element 80 brings the cutter blade 96 into position for severing the coils from the wire. A coil spring product 124 having large diameter coils 122 and smaller diameter coils 120 as shown in FIG. 12, are accordingly produced by the machine and severed from the stock wire as part of one complete automatic operational cycle.

In order to produce a coil spring with controlled coil pitch, the plunger 112 is replaced by one having a pitch control arm 116 longer than arm 116 so that its tip will be disposed behind the coiling point of the wire adjacent to the blade 82 as shown in FIGS. 13 and 14. Cam members 104 and 108 are selected with appropriate profiles to reciprocate the arm 116 a desired distance determining the spacing between the coils 126 being formed.

It will be appreciated from the foregoing, that springs of special design and dimensional requirements may be manufactured with precision by the machine of the present invention. The number of coils formed in each spring will be determined by the ratio of the feed rate of the wire to the rotational speed of the forming element since one revolution of the forming element corresponds to the formation of one spring product severed from the stock wire. The axial displacement rate of the coil engaging plunger will determine the coil pitch. Furthermore, the diameter of the spring coils will be determined by the depth of the groove in the forming element which will also control the variation in coil spring diameter. The forming element is readily replaced in order to meet different spring design requirements. The guide plates may also be arranged so that the feed path of the wire is offset from the rotational axis of the forming element on the side opposite to that illustrated in order to form either a right-hand wound or a left-hand wound coil spring.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In a machine for coiling wire having means for feeding the wire and a forming element having a groove into which the wire is fed to bend the wire into coils, means rotatably mounting said forming element about a fixed axis, means engaging said coils for regulating pitch during formation thereof, guide means through which said wire is fed along a path intersecting the forming element for regulating the bending of the wire, and drive means connected to the forming element for rotation thereof in synchronized relation to said feeding of the wire to control the diameter of the coils as a function of the depth of the groove in the forming element.

2. In a machine for coiling wire having means for feeding the wire and a forming element against which the wire is fed to bend the wire into coils, means rotatably mounting said forming element about a fixed axis, means engaging said coils for axial displacement thereof in parallel spaced relation to said fixed axis, guide means through which said Wire is fed along a path intersecting the forming element in offset relation to the fixed axis for regulating the bending of the wire, drive means connected to the forming element for rotation thereof in synchronized relation to said feeding of the wire and said axial displacement of the coils by the coil engaging means, and cutter means mounted by the forming element for severing a predetermined number of coils from the wire being fed to the forming element.

3. The combination of claim 2 wherein said forming element comprises a cylindrical member having an external groove receiving said wire from the guide means, said external groove having a root diameter controlling the diameter of said coils.

4. The combination of claim 3 wherein said cutter means comprises a blade projecting radially from the cylindrical member and extending transversely across the external groove at an angle to the fixed axis.

5. The combination of claim 4 wherein said drive means comprises a motor connected to the feeding means for advancing the wire at a predetermined feed rate, a drive shaft connected to the forming element and driven by the motor, and cam means mounted by the drive shaft and engageable with said coil engaging means for displacement of the wire into the path of said cutter means.

6. The combination of claim 5 wherein said external groove in the cylindrical member includes portions of different root diameter to form coils of different diameters.

7. The combination of claim 1 wherein said forming element comprises a cylindrical member within which the groove is formed with a varying depth.

8. In a machine for coiling wire having means for feeding the wire and a forming element against which the Wire is fed to bend the wire into coils, means rotatably mounting said forming element about a fixed axis, means engaging said coils for axial displacement thereof in parallel spaced relation to said fixed axis, guide means through which said wire is fed along a path intersecting the forming element in offset relation to the fixed axis for regulating the bending of the wire, drive means connected to the forming element for rotation thereof in synchronized relation to said feeding of the wire and said axial displacement of the coils by the coil engaging means, said forming element comprising a cylindrical member having an external groove receiving said Wire from the guide means, said external groove having a root diameter controlling the diameter of said coils, said external groove in the cylindrical member including portions of different root diameter to form coils of different diameters.

9. The combination of claim 7 wherein said drive means comprises a motor connected to the feeding means for advancing the wire at a predetermined feed rate, a drive shaft connected to the forming element and driven by the motor, and cam means driven by the drive shaft and engageable with said coil engaging means.

10. In a machine for coiling wire having means for feeding the wire and a forming element against which the wire is fed to bend the wire into coils, means rotatably mounting said forming element about a fixed axis, means engaging said coils for axial displacement thereof in parallel spaced relation to said fixed axis, guide means through which said wire is fed along a path intersecting the forming element in offset relation to the fixed axis for regulating the bending of the wire, drive means connected to the forming element for rotation thereof in synchronized relation to said feeding of the wire and said axial displacement of the coils by the coil engaging means, said drive means comprising a motor connected to the feeding means for advancing the wire at a predetermined feed rate, a drive shaft drivingly connected to the forming element and driven by the motor, and cam means mounted by the drive shaft and engageable with said coil engaging means for automatically varying coil pitch.

11. The combination of claim 10 including cutter means mounted by the forming element for severing a predetermined number of coils from the wire being fed to the forming element.

12. The combination of claim 10 wherein said forming element comprises a cylindrical member having an external groove receiving said wire from the guide means, said external groove having a root diameter controlling the diameter of said coils.

References Cited UNITED STATES PATENTS 725,723 4/1903 Kirk 72138 1,843,240 2/1932 Owen 72138 X 1,863,916 6/1932 Ziler 72-138 X 1,930,329 10/1933 Xinar 72-138 X 2,110,665 3/1938 Herlman et al. 72138 X 3,195,338 7/1965 Bram 72-138 MILTON S. MEHR, Primary Examiner US. Cl. X.R. 72-1 3 8 

